Apparatus and method for testing and assorting thin rubber goods



Nov. 12, 1940. J R M R 2,221,323

APPARATUS AND METHOD FOR TESTING AND ASSORTI'NG THIN RUBBER GOODS 9 Sheets-Sheet l Filed Aug. 22 1938 Jenn R. Gamma-ran Nov. 12, 1940. .1. GAMMETER 2,221,323 I APPARATU AND METHOD FOR TESTING AND ASSORTING THIN RUBBER GOODS Filed Aug. 22, 1958 e'sheets-sheet 2 Nov. 12, 1940. JQRTG'AMMETER APPARATUS AND METHOD FOR TESTING AND ASSORTING THIN RUBBER GOODS 9 Sheets-Sheet 3 Filed Aug. 22,- 1938 2 m .b6 5 w .w P m ,0 3 w F, A. 3 G 8 44 E 3 mm 3 HGHE '5 4 F JOHN R. Ganheweg J5 R. GAMMETER APPARATUS AND METHOD FOR TESTING AND ASSORTING THIN RUBBER GOODS 9 sheets-sheet 4 w W C M 4" W 1% i 7 [b 5 9 5 u w h 60. 1 Wm 36 6 .flluu u A m4 n U 9 o 2 .4 3

Jam R. GAMMVETER NOV. 12, 1940. J R A M TE 4 2,221,323

APPARATUS AND METHOD FOR 'I'ESTING AND ,AssORTING THIN RUBBER GOODS File'd Aug. 22, 1958 9 Sheets-Sheet 5,

John R. GAMMETER NOV. 12, 1940. V G M 2,221,323.

' APPARATUS AND METHOD FOR TESTING AND ASSORTING THIN RUBBER GOODS I Filed Aug. 22, 1938 9 Sheets-*Sheet 6 H JO V Nov. 12, 1940. J. R. GAMMETER 2,221,323

APPARATUS AND METHOD FOR TESTING AND ASSORTING TH'INRUBBER GOODS I Filed Aug. 22 .1938 A 9 Shets-Sheet 7.

FIG. \2

NOV. 12,1940. J VR "GAMMETER 2,221,323

APPARATUS AND METHOD FOR TESTING AND ASSORTING THIN RUBBER GOODS I Filed Aug. 22, 1938 9 Sheets-Sheet a FIG. IA

42 at 4-5 23 ga l4-0 Ill: 38 9t 83 32 a 32" A 19 Joan RGRMMETER Nov. 12, 194i). J R GAMMETEER w 2221.323

APPARATUS AND METHOD FOR TESTING AND ASSORTING THIN RUBBER GOODS Filed Aug. 22, 1958 9 Quests-Sheet 9 Patented Nov. 12,1940

APPARATUS AND AND ASSORTING METHOD FOR TESTING THIN RUBBER GOODS John a. Gammetcr, mu, Ohio I Application August 22, 1938, Serial No 226,112

- 9 Claims. "(01. 209-81) The invention herein disclosed relates to thin rubber goods, procedure and apparatus and partrcularly to testing of such goods'and branding of such goods after manufacture, the particular 5 embodiment of the invention being designed for testing, discarding defective goods and branding the perfect goods after manufacture thereof and before shipment. The invention, however, may comprise separate procedures and separate in- 1 strumentalities for the respective purposes stated.

One purpose of the invention is to provide an mproved procedure and apparatus for testing thin rubber goods such as prophylactic rubber articles for imperviousness.

Another'purpose of the invention is to provide improved procedure and apparatus for discarding defective goods.

Another purpose of the invention is to provide improved procedure and apparatus for branding 20 the perfect goods.

Another purpose of the invention is to provide improved procedure and apparatus for delivering the tested or branded goods to a point for further treatment, packaging, etc.

The foregoing and other purposes of the invention are attained in and by use of the apparatus illustrated in the accompanying drawings and described below. It is to be understood that the invention is not limited to the specific 3 form thereof shown and described.

0f the accompanyin drawings: f

Figure 1 is a plan view, partly broken away and in section, of apparatus embodying an adapted to carry out the invention;

Figure 2 is a section on line 22 of Figure 3 is a section on line 33 of Figure 1; Figure 4 is a section on line 4-4of Figure 3;-

Figure 5 is a section on line H of Figure 3; Figure 6 is a section on line H of Figure 3;-

v Figure '7 is a section on line |-'I of Figure 5';

Figure 8 is an enlarged plan of the device at a testing station;

Figure 8' is a view on line M-i, of Figure 14;- Figure 9 is a part elevation, partly in section,

45 of the device at line 3-4 of Figure 1;

' Figure 10 is a section on line "-4. .of Fig ure 1;

Figure 11 ure 10; p

Figure 12 is a section on line 12-42; of Fig Figure 13 is a section on line lt-llof 'Fi8- Figure 14 is a part elevatiompartly in aectiony:

55 online I4-l4of1 'igure1; i

is a section on line l| -ll of Figure h" charged from Figure 15 is a section on line l5-.i5 of Figure 14;

Figure 16 is a section on 14; and

Figure 17 is an for the equipment.

Referring to the drawings, the numeral 20 designates a suitable table with legs 2|,2l and about the periphery of which is arranged "an annulus 22 which is'revolved about the table 20. annulus 22 may be supported on driven rollers 23, 23 on shafts 24 journaled on the under side of the table 20 and driven-by gears 25, 25 meshed with gears 26,526 in turn driven by sprockets 21, 21 about which is trained'a common chain 28. Chain 28 is trained about a driving sprocket 29 which is driven through a suitable reduction 30 driven by a pulley 3i overwhich is trained a'belt 32 driven by the pulley 32 on the shaft of a motor 33. This arrangement is such that annulus 22 will be continuously revolved line lG-IS of Figure 7 about table20 during use of the machine.

Annulus 22 carries thereon a circumferential series of equally spaced forms 34, 34 which are thereby arranged to be moved through several 25 stations at which various operations are performed. The forms 34, as best shown in Figures 3 and 4, are so shaped as to receive the articles to be tested and to hold them in distended unwrinkled condition. for applying to the forms goods to be tested. At station B is an electrical testing unit and device for manifesting a defective piece of goods so that itmay be discarded. At station 0 there is provided apparatus for goods. At station D is apparatus for branding perfect tested goods. At statlo'nE perfect goods may be rolled off the forms 34 and at station F perfect tested goods may be automatically disthe machine point for further handling, packaging. etc. A second set of these stations (not shown) may be arranged at the opposite side of table llso that the single machine may be used for simultaneously testing, branding. etc.,

thereto at two separate points. i

The forms are rotatably mounted on tubular spindles 35 which are secured in mountings 36 hinged on supports or brackets 31 mounted on annulus 22 whereby forms 34 may be swung between upwardly inclined positions as at station A (the right=hand side of Figure 2) and stations E and F andhorizontal positions as, at stations B, C and D, the forms being arranged to extend inwardly over the outer edge of table 20 for driving 15 A station is provided at A discarding the defective 35 and delivered to 9.40

goods supplied 46 electrical and wiring diagram 5 The 10 operation of the various testing, branding and other devices thereon as annulus 22 revolves. Springs 36 may be utilized normally to urge the forms 34 downwardly to horizontal position (see Figure 3).

As best shown in Figure 10, the forms 34 which are hollow and having openings 34 from the interior thereof to the outer surfaces at the tips of the forms (see Figure 3) and are so mounted that air under pressure may be supplied to the forms as at stations C and F for blowing the goods ofi the forms. To this; end the tubular spindles 35 are each connected by tubular hinge in 38 and duct 39 therein to a duct 40 with which duct 39 is in communication in all positions of forms 34. Duct 40 is in turn in communication with a duct 4| down through annulus 22 which is arranged to cooperate with air supply nozzle 42 or 42 at stations C and F as will be later explained (see Figures 10 and'15).

For holding forms 34 upwardly as they pass through stations A, E and F, plungers 43, 43 are provided (Figure 10) which are vertically slidable in the hinge brackets 31 so that the upper ends thereof may engage buffers 44, 44 on the under side of mountings 36 (see Figure 15). The plungers 43 carry rollers 45 (see Figures 10 and 15) which ride on cam rails 46 and 4'! which respectively extend through adjoining stations corresponding to E and F at the opposite side of table 20 and adjoining station A and through adjoining stations E and F as shown and the adjoining station opposite to and corresponding to station A, rails 46 and 41 being identical as will be apparent and being shaped to permit lowering of the forms as they pass to stations B, C, D and the corresponding stations (not shown) at the opposite sides of the table and being shaped to raise the forms and to hold them raised as they pass through stations E and F and the station opposite A and as they pass through stations opposite E and F and station A.

At stations B, C and D and opposite stations there is provided arcuate racks 48 for engaging gears 49 on forms 34 to revolve the forms as they pass through these stations.

At station A, the forms extend upwardly (see Figure 2) and there are no instrumentalities here which directly cooperate with the forms. One or more operatives may be placed at this station for applying goods G, such as prophylactic rubber articles, to forms 34 which are so shaped as smoothly to receive these goods, preferably under a slightly stretched condition $10 that they lie smoothly and without wrinkles on the forms 34.

Between stations A and B (and corresponding opposite stations) the cam rail 46 (and corresponding rail 41) are so formed as to lower the forms so that they ride with gears 49 on racks 48.

At station B (see Figures 1 and 3 to 8) there is provided an electrical testing unit and device for manifesting defective goods. This unit as best shown in Figures 1 and 3 to 81, inclusive, comprises an electric conductor element 5| which may be connected to a source of high tension electricity as will be described and which is adapted to be engaged by forms 34 carrying rubber goods G and to shape itself about and conform to the shape of the forms along a length of the form and down about the end of the form (Figures 3 and 4). Forms 34 are also electrical conductors connected in the high tension circuit with the element 5| so that a high electrical potential is present between the element 5| and a form 34 thereunder, which are separated only by the non' conducting goods G. This potential is suflicient to leap an air-gap of the thickness of goods G, but not sufficient to pierce the goods, except when the latter have thin spots or are under gauge. Hence goods with the smallest of pin-holes or under gauge areas therein 'will permit a current to flow in the high tension circuit.

Element 5| may be of any suitable electrical conducting material adapted to shape about and conform to the shape of the forms. However, a fine-mesh, flexible fabric of a type which has been often used in womens hand-bags has been found to be the most satisfactory and element 5| as shown comprises a sheet of this material.

The sheet material comprising element 5| has secured along its side or radial edges (with relation to the table) metal binder strips 52 which are secured by screws 52 to L-shaped supports 53, 53 of rubber covered metal, screws 52 being secured in the metal of the supports so as to electrically connect element 5| therewith.

The inner ends of strips 52 are downwardly curved as shown (Figure 3) and the material of element 5| is arranged to sag between supports 53 (see Figure 4) so that the material will shape about and conform to a length of the form and the end thereof as shown whereby a pin-hole or an under-gauge area anywhere along this element 5| is short of the upper or mouth end of goods G (Figure 3) by a substantial distance so that the air-gap between element 5| and the bar portion of form 34 is too great for passage of current.

Supports 53 are secured upon a crossbar 54 which is mounted on insulating blocks 55, 55 which are adjustably secured on table 20 by being slotted as at 56, 56 (Figures 1 and 8) and are secured in adjusted positions by screw bolts 51, 51 threaded into table 20. This adjustment provides a means'of bringing element 5| into proper relation with the forms 34.

In order to protect operatives from being shocked byaccidentally touching element 5|, a protective cover plate of glass or other dielectric is mounted on supports 53 (see Figures 3, 4 and 8), as indicated at 58. m

Associated with each form bracket 31 is a solenoid-operable magnetic plunger 59 (see Figures 3, 6 and 7) having thereon an outer grooved head 59 projecting outwardly of annulus 22 and which is arranged as shown in Figure '7 to move outwardly from the position there shown under influence of a solenoid, a shoulder at 59 coming in contact with a shoulder 59* to limit outward movement and a shoulder 59 on the head 59 coming in contact with shoulder 59 to limit inward movement of plunger 59. Head 59 is engageable by a cam 60 (Figures 8, 8 and 14) after an extended plunger 59 passes station F for returning each plunger. Cam 60 is mounted on a support or bracket 6| extending outwardly from table 20 and then'upwardly to the outer side of annulus 22 (see Figure 8 Associated with the element 5| at each station B is a fixed solenoid 62 which may be mounted on a bracket 63 extended outwardly from table 20 under annulus 22 and then upwardly beyond the outer periphery of annulus 22 to align solenoid 62 with the passing magnetic plungers 59.v

Solenoid 62 is so located as to pull out a plunger when it is energized and just after a form 34 carrying defective goods G passes out of contact with element 5| and before a secojd form with Associated with the equipment at each station 3 is a normally-closed switch 84 mounted on a pivot 65 and angularly adjustable to a fixed position by a bolt 86 extending through an arcuate slot B'I in a plate 68 on bracket 53. Switch is operable by a button 89 arranged when depressed to open the circuit through the switch and fortemporarily depressing button 89 there is a spring arm I connected to a lever 'II pivoted at 85 and carrying a cam I2 arranged to be engaged by a projecting plunger head 59 to swing lever II and consequently arm I0 downwardly to depress button 89. An extension 13 on lever 'II has an aperture therein through which loosely extends a screw I4 secured in a lug 15 on plate 88, providing means for limiting swinging movement of lever II in either direction.

Station C is provided for discarding defective goods. At this station is a. funnel I6, similar in shape to a ship's funnel which extends down through table 20 to a chute receptacle or the like (not shown) where scrap is received and which has a mouth at 11 opening in a direction radially outwardly of table 20 in line with the inner ends of forms 34 as they pass through station C. As best shown in Figures 9, 10 and 11, air-pressure supply nozzle 42 is yieldingly held by springs I8, I8 against the under side of annulus 22 so as to cooperate with ducts II and to be in communication with the interior of forms 34 and with the ports or outlets 34 at their ends, the nozzle 42 being thus yieldingly supported on a bracket I9 and guided for vertical shifting movement as required to ride against the revolving annulus by pins 80, 80 in the nozzle engaged inslots 8| in bracket I9. Bracket I0 extends inwardly under and is secured to table 20.- A flexible conduit 82 is connected by a nipple 83 to nozzle 42 and extends to a control valve 84 of a known type, which is electrically operable by well-known means housed at 85. A branch sup- 45 ply line 88 is connected to valve 84 and a main air-pressure supply line 81 may be extended down through table 20 (see Figure 2) and may be suitably connected to various branch supply lines such as line 86.

J 50 For operating valve 84 to blow a piece of defective goods G 011 a form 34 as it passes through.

station C and into the funnel I8, a switch-operating arm 88 is provided having thereon a cam 89 engageable by a passing projecting plunger head 59 to depress lever or arm 88. Arm 88 is secured on a shaft 90 joumaled in a tube 90 secured in brackets 9|, 9| fastened on a plate 9I in turn secured to the under side of table 20. Fixed on the inner end of tube 9|! is a housing 92 in which are switch contacts 93 and 94, contact 93 being fixed and contact 94 being carried on an arm 95 pivoted at 96 and yieldinglyurged toward contact with element 93 by a coil spring as at 91; a pin 98 onarm 95 riding on a-cam 9 9 secured'on shaft 90. Shaft 90 (see Figure 11) has secured thereto an arm I00 which is yieldingly urged by spring IN to hold arm 88'upwardly to be engaged and depressed by a plunger head 59 and to normally hold cam 99 in a position such that switch contacts 93 and 94 are open as shown, movement of arm I00 and consequently of 'arm 88 upwardly limited by an adjustable screw- I02 threaded through arm I00 and arranged to contactany fixed part such as plate 9|;

"n The branding device. at station D comprises. as

. 3 best shown in Figures 9, 12 and 13, a stamp I03- arranged on a suitable universal mounting I04 and adjustable to a level position thereonby a screw I05 secured in the back of the stamp I03 in a spherical recess I06 fitting on the corresponding spherical top of the mounting I04, the stamp being secured on it's mounting by thumbnut WI. The stamp I03 is so mounted that forms- 34 carrying tested goodsG from the discarded station C are rolled over the face of the stamp by rotation of gears 49 by-rack 48 and the desired branding on the stamp is applied to the goods. In order to apply ink to the stamp an inking pad I08 may be so secured on an arm. I09 in turn secured on a. vertically reciprocable rod H0 mountedin a bearing I I I in table 20 and operable by a crank H2, the latter being pivoted at H0 to rod H0 and secured on a shaft H3 journaled in. a tube II4 mounted on brackets H5,. H5 on the under side of table 20. Shaft H3 thus extends outwardly to a'position under the inner edge. of annulus 22 on which is mounted a cam ring H8 formed with-spaced relieved portions at H8, an arm I I! on the outer end of shaft H3 carrying a roller H8 yieldingly held by the weight of the parts, or otherwise, against the lower edge of cam ring I I6. I Roller H8 is thus arranged -to ride up in. a relieved place H6 in cam H6,

one being arranged just in advance of each form 34 so as to lower pad I08 onto stamp I03 to ink the stamp just pefore each piece of goods G are rolled over the stamp. So as not to apply ink by stamp I03 onto an empty form 34 from which defective goods has been blown at station C,

flow of electricity to a solenoid at I23 operating a core or plunger I24 connected at I25, I25 to a vertically reciprocable member I28 journaled at I2'I on table 20 and carrying on its upper end a track I28 with ramps at I29 and I30 whereby upon passing of an empty form 34 to the branding device track I24 will be raisedinto the path of the forms and the empty form will roll up ramp I29 along track I28 and down ramp I30 to pass over but not contact stamp I03. Cam H9 is of the substantial length shown to hold solenoid I23 energized from a time just before passage of an empty form to station D until the time said form has passed from station D.

Station F merely is a location where forms 34 are elevated as shown and one or more operatives here may strip the goods G from the forms by reversely rolling them upon themselves from their open ends.

The equipment at station F is designed automatically to remove the tested and branded goods from the machine as shown best in Figures 14, 15 and 16 and comprises a funnel I3I similar to funnel 11 but arranged with its mouth to receive.

goods blown from forms 34 while said forms are extended inwardly and upwardly (see Figures 1, 2, 15 and 16) the forms passing through this station being held upwardly by cam rail 48 acting on rollers 45 on plungers 43 as has been described. Nozzle 42 is-similar toj nozzle 42'and is suitably controlled to blow air into the forms by substanpositions shown the cam 89 is engaged by plunger heads 59 of plungers which have not been drawn outwardly by solenoid 62 and which carry, therefore, perfect tested and branded goods.

To make arm 88 adjustable on its shaft 90, the outer end of shaft 9|] has secured thereto a sleeve I32 (see Figure 16) in which is longitudinally shiftable a shaft I33 carrying in a socket I34 an outwardly spring pressed ball I35 for locking shaft I33 to sleeve I32 in either of two longitudinal positions by engagement with apertures I36 and I3! in sleeve I32. Shaft I33 carries arm 88 and said shaft is arranged to be shifted carrying the arm with it, by means of a knob I38 connected to shaft I33 and extended to the outside of the machine for manual operation. A pin I39 secured to arm 88 extends through a flange I40 on sleeve I32 and has a shoulder I39 thereon to limit outward shifting of arm 88. 4

The electrical connections to the simple solenoid-operated valves and their. control switches such as valve 84-85 and switch 93-438 will be well understood by skilled artisans. Figure 1'7, however, illustrates the electrical connections for the testing device at station E and the solenoid for operating, plungers 59. A brief description of this diagram follows in the next paragraphs.

An ordinary source of A. C. electricity is connected to a transformer T-I designed to produce a high tension current of low amperage, one high tension lead for transformer T--I being connected through suitable resistance RI to retard current flow to the metallic fabric mesh St. The other side of transformer TI is connected at station B through a, suitable resistance R2 to the forms 34 (as for example through rack 88 and gears 49) and to the ground (e. g. grounded on the machine).

One line of a shunt off the grounded high tension line of the transformer (which is connected to the forms) conveys a current through a suitable resistance R 3 to the grid of a trigger tube X and the other line of the shunt connects to the filament circuit of that tube which extends to the output side of a suitable transformer T-2 'also connected to an ordinary power source on its input side. The plate of tube X is connected through suitable resistance R-d to one side of the solenoid or electromagnet 62, a shunt S containing reactance being provided across the coil of solenoid 62. connected through switch 64 to one side of a suitable rectifier Y, the other side of the rectifier Y being connected to the output circuit of transformer T-2 supplying the filament of tube X. A suitable r eactance S-I may be arranged across the rectifier Y which may be connected through a suitable transformer T3 with an ordinary source of A. C. electricity. A shunt S2 across the filament and plate of tube X contains a suitable resistance and condenser in parallel.

The other side of solenoid 62 is 7 The foregoing circuit and associated instrumentalities are so connected that so long as the 7 grid of tube X is not energized by passage of current through the grid, no D. C. electricity can fiow from rectifier Y across filament and plate and through solenoid 62 which remains unenergized. Upon the flow of current through the grid in the A. C. circuit including transformer TI, element 5| and a form 34, even though this flow is of very short duration, a D. C. current flow is established from rectifier Y across the filament and plate and energizes solenoid 62, and even after discontinuance of the A. C. flow, this D. C. flow continues until the D. C. circuit is broken. Thus solenoid E2 is energized when a hole or under-gauge area is found in goods G and remains energized from that instant until the form carrying such goods passes from engagement with element 5|, thus the solenoid draws out a plunger 59, the head 59 of which immediately actuates switch 64 opening the D. C. circuit before a succeeding form 34 engages element I5 and thereby setting the circuit in its original condition for subsequent testing of the passing goods.

In the operation of the device, an operative or operatives standing at stations A will slip the goods G to be tested over the forms 34, the forms then extending inwardly and upwardly to facilitate these operations. The forms then pass to stations B and as they do so swing downwardly to inwardly-extending horizontal positions in which they pass under element 5| which shapes itself to conform to the shape of the forms. The forms are so spaced that only one form can be in contact with the element 5| at any given time.

If perfect goods are on the forms, these will prevent the passage of a high tension current between element SI and the forms and will pass along for succeeding operations in the machine. If, however, imperfect goods are on the forms, these permit the flow of electricity in the A. C.

circuit and cause the solenoid 62 to be energized branding device at station D where they will roll over the stamp I03 and will be branded as will be understood, the stamp being intermittently inked between passage of the forms. Imperfect goods, however, will, because of the extension or projection of plungers, 59, be blown off the forms into funnel I6 at station C and plungers 59 cause the track I28 to be elevated as empty forms pass from station C to station D whereby the empty forms will roll over the stamp I03 without contacting the same.

If rolled goods are required one or more operatives may be arranged at station E to roll tested goods off the forms. If fiat-packed or bulk goods are desired, knob I38 which is pulled out to prevent operation of the equipment at station F is shoved in (see Figure 16) to set this equipment in operation so that the perfect tested goods will pended claims.

' for testing a series of articles in succession and What is claimed is:

1. Apparatus of the class described comprising the combination in a device for testing thin hollow flexible rubber articles, of electrical means including a series of forms for the articles on which they may be supportedin distended unwrinkled condition, means for conveying the forms, and an electrical element with which the forms cooperate in succession to contact the articles thereon, mechanical means responsive to and operable by said electrical. means to manifest the presence of defective goods on the forms, means operable by said mechanical means on the forms in succession after testing to discharge de-v fective goods from the forms, and other means also operable by said mechanical means after testing for discharging perfect goods from said forms.

2. That methodfor testing thin 'flexlble hollow rubber goods or the like for defects, .which comprises providing smooth electro-conductive rotatable forms on which the goods may be slipped under suflicient tension to hold them distended without wrinkling, fitting the goods over said forms, applying an electro-conductive element to the surfaces of the goods on the forms, rotating the forms while contacting said element, and maintaining a high potential of electricity between said element and said forms sufficient to leap an air gap comparable with the thickness of the goods but insufiicient to pierce goods of normal thickness.

3. That method for testing thin hollow flexible rubber articles or the like for defects, which comprises fitting such articles over a rotatable form of electro-conductive material, said form distending the articles so as not to have wrinkles therein, applying an element of electro-conductive material about said articles which shapes about and conforms to the surfaces of the goods on the forms, rotatingthe form while in contact with said element, and maintaining a high electric potential between said element and said form suificient to leap an air gap comparable with the thickness. of the goods but insufficient to pierce V goods of normal thickness.

means for rotating said form while in contact with said element, and means for establishing a high'potential of electricity between said ele-* ment and said support sufficient to leap an air gap comparable with the thickness of the goods but of insufficient potential to pierce goods of normal thickness.

5. Apparatus for testing thin hollow flexible.

rubber articles or the like comprising an electro-conductive form on which the article may be fitted in distended unwrinkled condition, an-element of electro-conductive material applicable to said form and shaping about and conforming to the surface of the article on the form, means for rotating said form while in contact with said tential of electricity between said element and said form sufficient to leap an air gap comparable to the thickness oi!v the article but of insuflicient potential to pierce an article of normal thickness.

6. Apparatus for testing thin flelxlble hollow rubber goods or the like for defects comprising an electro-conductive form for fitting the goods thereon inv distended unwrinkled condition, an electro-conductive element applicable to the surface of said goodsand conforming to the shape of the form, means for rotating said form while in contact with said element, means for establishing a high ,potential of electricity between said element and said form sufllcient to leap an .air gap comparable with the thickness of the goods but of insufficient potential to pierce goods of normal thickness, and means for manifesting the passage of electrical current between said elements.

'7. Apparatus for testing thin hollow flexible rubber articles or the like each of which has a closed end comprising an electro-con'ductive form on which the article may be placed in distended unwrinkled condition, said form having an end over which the closed end of the article is supported, an element of electro-conductlve material applicable to said form and shaping about and conforming to the surface including the.

element, and means for maintaining a high 130-- closed end of the article on the form, and means for maintaining a high potential of electricity between said element and said form sufficient to leap an air gap comparable to the thickness of the article but of insuflicient potential to pierce an article-of normal thickness, said element comprising a flexible, metallic mesh fabric, and means for mounting said fabric in sagging condition, whereby it will shame about a side and closed end of the article. a

8. Apparatus as set forth in claim 5, comprising a series of such forms, and means for conveying said forms in succession into association with said element. 4 I I 9. Apparatus as set forth in claim 7, comprising a series of such forms, means for moving said fOriDfllh: succession in associati n with said element, and means for rotating said forms while they pass in contact with said element to test the articles all about the forms. 

